Encoders, formatters, JWT and regex tools, and generators support developers in APIs, config, and debugging.
Convert text to Base64 format and decode Base64 strings
Format, validate, and minify JSON data with syntax highlighting and error detection
Inspect JSON in an interactive tree. Expand and collapse nodes, copy paths, and view formatted JSON.
Compare two JSON documents with structural path diff and formatted line diff. Client-side only.
Semver-aware package.json dependency diff and npm lockfile version map, plus full JSON structural diff.
Generate a starter .editorconfig with indent, EOL, charset, and language presets. Copy-ready.
Paste NDJSON or logs with embedded JSON. Filter by level, search, expand objects, and copy. Client-side only.
Parse Content-Security-Policy values, explain directives, flag common weak patterns, and copy an advisory stricter draft.
Generate Subresource Integrity hashes for script and link tags from a URL or file upload. SHA-256 and SHA-384.
Educational: from HTTP method and request headers, see if a cross-origin request would likely trigger a CORS preflight. No server calls.
Convert between YAML and JSON formats with validation and formatting
Convert XML to JSON and JSON to XML with validation and formatting controls. Client-side conversion for API payloads and integration workflows.
Format and validate YAML with consistent indentation. No conversion to JSON.
Build HTTP requests with URL, method, headers, and body. Send or copy as cURL or fetch snippet.
Parse raw HTTP response headers online. Paste from DevTools or curl, inspect CORS and cache headers, copy any value.
Check SSL/TLS certificate validity, issuer, subject, and SANs. Paste PEM or upload .pem/.crt. Client-side only.
Check WCAG contrast ratio between foreground and background colors. See AA and AAA pass/fail for normal and large text.
Create copyable agendas for standups, sprint planning, retros, 1:1s, and kickoffs. Set duration and project name.
Compare team capacity and committed story points. Sprint length, team size, capacity %, optional velocity.
Generate timeboxed retro agendas: Start/Stop/Continue, 4Ls, Mad/Sad/Glad, Sailboat. Set team size and duration.
Calculate price per unit from total price and quantity. Compare two products to see which is cheaper per oz, kg, or any unit.
Calculate subnet mask, network address, usable range, and broadcast from CIDR notation (e.g. 192.168.1.0/24).
Validate JSON data against a JSON Schema. See errors with path and message.
Format and validate .env files. Normalize KEY=value, optional sort, check for duplicate keys.
Format and validate GraphQL documents (SDL and operations). Pretty-print and check syntax in your browser.
Check that your XML document and XSD schema are well-formed. Paste both and validate syntax.
Validate OpenAPI 3.x and Swagger 2.0 specs (YAML or JSON). Check required fields and structure.
Format and validate CSV or TSV data. Delimiter, quote style, trim. Check column consistency.
Look up MIME type from file extension or extension from MIME type. Browse common types.
Format and validate TOML. Re-serialize with consistent structure. No conversion to JSON.
Format and validate INI config files. [section] and key=value, optional sort, no duplicate keys.
Format shell and bash scripts. Indent and normalize. Runs in your browser with shfmt (WASM).
Convert between TOML and JSON with validation and formatting. Free TOML to JSON and JSON to TOML for Cargo, pyproject.toml, and config files
Convert between text and different number systems
Generate realistic sample data for testing, development, and prototyping with customizable schemas
Convert text between different casing conventions
Encode and decode HTML entities
Encode and decode URL components
Convert between Base64 and Image formats
Generate MD5, SHA1, SHA256, and SHA512 from text or file upload. File hash, checksum from file, verify file integrity. Client-side only.
Generate custom QR codes for URLs, text, contact info, and more with customizable colors and sizes
Generate secure, random passwords with customizable length, character types, and strength indicators
Convert between Unix timestamps and human-readable dates. Relative time: "in 2 hours", "3 days ago", "next Monday" to date, or date to relative. Timezone support.
Convert numbers 1–3999 to Roman numerals and Roman numerals to numbers. Two-way conversion with validation.
Generate RFC 4122 compliant UUIDs (v1 and v4) with multiple output formats for databases, APIs, and applications
Convert titles and phrases to URL-friendly slugs: lowercase, hyphenate, strip diacritics for URLs, CMS, and SEO
Convert ticket titles and feature names to valid git branch names: lowercase, hyphenate, strip invalid characters
Pick stacks and merge starter .gitignore, .dockerignore, .npmignore, .eslintignore, .prettierignore, or .cursorignore patterns. Copy-ready in your browser.
Escape and unescape text for JavaScript, JSON, HTML, XML, SQL, and regex. Safe string encoding for code and queries.
Compare two text or code snippets side-by-side or unified. Line numbers, ignore whitespace. Paste or type to diff.
Format and minify CSS. Beautify or collapse whitespace, remove comments. Free, client-side, no sign-up.
Compare two semantic versions and check if a version satisfies a range (e.g. ^1.2.0). Free online version compare for developers.
Convert Markdown to HTML and HTML back to Markdown. Support for headers, links, images, code blocks, lists, tables, and more
Count character or word frequency in text. Sort by count or name. Ignore case, spaces, or punctuation.
Count words, characters, sentences, and paragraphs in your text
Sort lines in ascending or descending order, remove duplicates, and strip blank lines
Decode, encode, and verify JWT with HS256 or RS256. Explain standard claims in plain language.
Decode JWT, inspect claims, and verify RS256-family signatures against JWKS keys using kid matching. Client-side only.
Generate and compare HMAC signatures for webhook and API request debugging. Supports SHA-256, SHA-384, and SHA-512 with hex or base64 output.
Verify webhook signatures for GitHub, Stripe, Slack, and generic HMAC payloads. Compare expected and received signatures instantly.
Decode PEM-encoded X.509 certificates. View subject, issuer, validity dates, and SANs – client-side only.
Inspect PEM CSRs and PKCS#8 private keys: subject, algorithms, RSA bits or EC curve. Client-side only.
Build, test, and debug regular expressions with instant match highlighting and flag support
Convert between CSV and JSON formats with smart parsing, custom delimiters, and file upload/download support
Test your clicks per second (CPS) with a timed click test. Choose 5 or 10 seconds and click as fast as you can. Free online click speed test.
Free online click counter. Count clicks with a simple +1 button. Add an optional label and reset anytime.
Free online scoreboard for two teams. Add points with +1, +2, +3 buttons. Customize team names and reset anytime.
Flip a virtual coin online for heads or tails. Free coin flip simulator with flip counter.
Add options and get a random pick. Free online decision maker for quick choices.
Guided breathing timer with box breathing and 4-7-8 patterns for relaxation and focus.
Live world clock for major cities. Free online world time zone viewer with regional filters.
Compare time zones side by side, find overlapping meeting hours, and share the view with a link.
Create bar charts and line graphs online. Enter labels and values, choose bar or line chart. Free online chart maker.
Format, beautify, and validate SQL queries with syntax highlighting. Support for multiple SQL dialects including MySQL, PostgreSQL, SQLite, and more
Generate Lorem Ipsum or code placeholders: variable names, JSON keys, function stubs. Customizable paragraphs, words, and formatting.
Parse, validate, and decode URLs with detailed component breakdown. Extract protocol, hostname, path, query parameters, and fragments from any URL
Format, beautify, and minify JavaScript code with syntax-aware output and one-click copy
Format, validate, and minify XML with clean indentation, error highlights, and quick copy/download
Parse cron expressions into readable schedules and generate cron strings with upcoming run previews
Build cron expressions with presets or custom fields. Get human-readable summary and next run times.
Look up HTTP status codes by number or name—see meanings, usage, and copy codes instantly
Look up characters by code point or by character. Browse the ASCII table (0–127) with names and copy codes instantly
Generate starter CLAUDE.md, AGENTS.md, GEMINI.md, Cursor .mdc rules, and CONTRIBUTING.md-style conventions from project type and stack. Generic templates when fields are empty.
Parse browser, OS, and device from any User-Agent string. Debugging, analytics, and support.
Compress and optimize images in your browser. Reduce file size with quality control, format conversion (JPEG, PNG, WebP), and optional resize. All processing client-side.
Build structured LLM prompts with role, task, context, format, and constraints. Presets for explain, summarize, draft, and more. Copy-ready, runs in the browser.
Convert octal chmod modes to rwx permission strings, binary triplets, and ls-style output. Copy chmod commands with setuid, setgid, and sticky. Client-side only.
Generate Claude Code Agent Skills (SKILL.md) with presets, optional scripts and references, ZIP download, and setup steps for ~/.claude/skills/. Runs in the browser.
Compose structured system prompts for ChatGPT, Claude, and other LLMs. Presets for coding, tutor, support, and more. Copy-ready, runs in the browser.
Build OpenAI and Anthropic function-calling JSON from parameters. Types, descriptions, required flags, and enums. Runs in the browser.
Generate Cursor mcp.json and Claude Desktop MCP server config from command, args, and env vars. Presets for filesystem, git, fetch. Runs in the browser.
Count words and characters and estimate ChatGPT, Claude, and Gemini tokens. Context window gauge for 4K–200K. Runs in the browser.
Split long documents into chunks for ChatGPT and other AI chats. By characters, tokens, or paragraphs with overlap. Copy or ZIP download.
Software development is the site's second-largest toolset — 92 tools — covering the everyday encoding, formatting, and debugging utilities that developers reach for constantly but rarely want to write themselves.
Data format conversion is a major theme: the JSON Formatter & Validator, JSON Viewer, and JSON Diff handle the constant need to inspect, validate, and compare API responses and config files, while the YAML/JSON Converter and XML/JSON Converter bridge the format differences between config systems, legacy APIs, and modern JSON-based tooling. The Base64 Encode/Decode tool is a near-daily utility for inspecting tokens, embedded images, or encoded payloads during debugging.
Configuration and tooling round out a large portion of the set: the EditorConfig Generator helps teams standardize formatting rules across a repo, and the Structured Log Viewer makes sense of JSON-formatted application logs during quick local debugging without piping them through a separate log aggregator. Security and web-standards tools — the CSP Helper, SRI Generator, and CORS Preflight Explainer — help developers work through browser security policies that are easy to misconfigure and hard to debug from error messages alone.
What ties the 92 tools together is that they're all things a developer could technically compute or verify by hand or with a quick script, but doing so mid-task breaks flow. Having them as fast, no-install browser utilities — for encoding, diffing, formatting, or explaining a security header — fits naturally into a debugging or code-review session without switching to a terminal or writing throwaway code.